Apex error reference

Salesforce Apex errors — causes and fixes

Curated explanations of common Apex and SOQL errors, with the underlying cause and a concrete fix for each. Every page is written by a working Apex engineer, not generated. More pages added as we hit them in real codebases.

field 'recordname' is not marked queryable
Salesforce error when SOQL or the Tooling API selects a field whose IsQueryable metadata flag is false. Three causes — history tables, Tooling API metadata objects, and dynamic SOQL — with the fix for each.
UserInfo.getDefaultCurrency()
What UserInfo.getDefaultCurrency() actually returns in Apex, the difference between single-currency and multi-currency orgs, and how to read the corporate currency safely in both.
Method does not exist or incorrect signature
The eight things that produce this Apex compile error — typos, generic erasure, hidden statics, missing namespace prefixes, and more — with the diagnostic question and the fix for each.